Manual control mechanism



Leah! M Jan. 26, 1954 W. M NAMARA MANUAL CONTROL MECHANISM Filed June 12, 1951 Patented Jan. 26, 1954 MANUAL CONTROL MECHANISM William MacNamara, Philadelphia, Pa., assignor to Proctor Electric Company, Philadelphia, Pa., a corporation of Pennsylvania Application June 12, 1951, Serial No. 231,165

6 Claims.

This invention relates to manual control mechanisms, and more particularly to a mechanism for use in apparatus whose operation to be controlled by a manually rotatable member.

There are many instances in which starting and operating adjustment of some apparatus or device is effected through the medium of a manually rotatable member, such as a knob or dial. In many such instances, it is desirable that the manual member be readily removable, and it is also desirable that provision be made for indexing adjustment of the manual member relative to the member which it drives.

One object of the present invention is to provide a manual control mechanism which is capable of use in any such apparatus or device and which provides for easy removability of the control knob or dial, and also for indexing adjustment of the control knob or dial relative to the member actuated thereby.

Another object of the invention is to provide a manual control mechanism which is simple in construction and capable of low cost manufacture.

In a copending application of Robert J. Wagner and Harvey E. Hortman, Jr., Serial No. 231,224, filed June 2, 1951 there is disclosed a control apparatus for automatic operation of a pressure cooker, which apparatus employs a manually r0- tatable knob Or dial to initiate operation and to set the time of the pressure cooking operation. In that apparatus, the control knob or dial is operatively connected to a member which has a switch-controlling cam and a ratchet, and rotation of the dial from its off position initiates operation through said cam and also sets the ratchet for the desired cooking time. During timing of the cooking operation, the ratchet is actuated and moves the dial to the oil position.

A further object of the present invention is to provide a manual control mechanism which is particularly adapted for use in an apparatus of the character disclosed in the above-mentioned application.

A still further object of this invention is to provide, in such a control mechanism, means for obstructing the entry of grease or other foreign matter into the casing which houses the apparatus, and for preventing heated vapor or air from excessively heating the knob.

Other objects and features of the invention will be apparent from the following detailed description with reference to a preferred embodiment shown in the accompanying drawing.

In the drawing:

Fig. 1 is a plan View of the manual control mechanism, with a portion of the control knob or dial broken away for the sake of illustration;

Fig. 2 is a cross-sectional view taken along line 2-2 of Fig. 1;

Fig. 3 is a detailed sectional view taken along line 33 of Fig. 1;

Fig. 4 is a perspective View of the knob or dial;

Fig. 5 is a perspective view of the actuated member; and

Fig. 6 is a perspective View of a resilient element which serves to effect frictional attachment of the knob or dial to the actuated member, and which also serves to index the knob or dial relative to the actuated member.

Referring more particularly to the drawing, there is shown at It] a portion of a casing which may serv to house apparatus such as that employed for automatic operation of a pressure cooker as disclosed in the aforementioned Wagner et al. application. It will be understood that so far as this invention is concerned, the casing may be any casing serving to house an apparatus or device with which the present invention may be used. The casing I0 is provided with a circular opening H and has an extension l2 about said opening forming a wall to obstruct entrance of foreign matter, and cooperates to reduce heated air or vapor egress from within the casing. A member i3 is rotatably supported within the casing 10 and is intended to be rotated manually from outside the casing. For the purpose of illustration, there is shown a stationary member i4 disposed within the casing ill and supporting a fixed upwardly-extending stud i5, such structure corresponding to that utilized in the apparatus disclosed in the aforementioned Wagner et a1. application. Member 13 is rotatably supported by the stationary support I4, having a central aperture it?- through which the stud l5 extends and an annular flange 16a for bearing on the top surface of support It. A spring washer i1 bears against the upper central portion of member I3 and is held in place by a spring fastener l8 seated in an annular groove of stud l5.

As may be seen in Figs. 2 and 5, the member l3 has an annular projection is extending within the opening II in spaced relation to the wallforming extension I2. A resilient element 2a, which is preferably formed of flat spring metal, extends diametrically across the end of the annular projection l9 and is secured thereto by screws 2| which threadedly engage the annular projection l9. As may be seen in Figs. 3 and 6, the resilient element 20 has transversely elongated apertures 22 through which the screws 21 extend, said apertures permitting small rotary adjustment of the said element relative to the member l3. Said element has turned end portions 23 adjacent to the outer wall of the annular projection l9 and bowed outwardly from said wall.

A manually rotatable knob or dial 2A is of a size and shape to cover the opening ll and has an annular flange or projection 25 which is adapted to be inserted between the annular projection l9 and the wall it, the latter two providing a natural piloting action, as may be seen in Fig. 2. The flange 25 has diametrically opposed internal recesses 26 which serve to seat the bowed end portions 23 of the resilient element 20. When the knob or dial is applied, the walls of recesses 25 exert pressure on the bowed end portions 23, and the latter serve as springs to effect firm attachment of the knob or dial to the member it. The knob 24. is fully seated when its flange 25 engages the three bearing bosses Isa which are formed integral with member It. It will be apparent that the knob or dial, while firmly attached to the member 13, may be readily removed simply by applying sufficient force to overcome the frictional force asserted by the spring element 20.

It should be noted further that the end portions of element 20 and the cooperating recesses 26 of the dial or knob serve to index the latter with respect to the member 53, and the elongated apertures 22 enable accurate adjustment of the indexing of the knob or dial. This is important because it enables accurate and proper adjustment of the off position of the dial. As may be seen in Fig. 1, the casing it) has a stationary marker 21, and the dial has marker 28 which is intended to be aligned with the marker 2"! in the off condition of the apparatus. Since the member will have a definite position in which the apparatus is oii, it is important that dial 24 be accurately indexed relative to member [3 so as to align the markers 21 and 28 when member I3 is in the off position. Thus in the apparatus of the aforementioned Wagner et al. application, the dial-actuated member has a switch-actuating cam which opens a switch in one position of said member and closes the switch in other positions of said member. Moreover, the said member also has ratchet teeth and serves as part of a timer, and the dial has time setting indicia thereon. In such an apparatus, it is very important that the dial be accurately indexed relative to the actuated member, and the present invention provides for the necessary accurate indexing.

It should be pointed out that if it is desired to make the knob 24 of transparent plastic, e. g. Lucite, for appearance sake, it is important that the temperature of said knob be kept to some low value. The provision of flanges 25 and I3 and the annulus formed between flange 13, the inner peripheral edge of knob 24 and the top of casing act to prevent heated vapor or air from causing excessive temperature rise to the knob. The use of transparent material for knob 24 makes it advantageous to utilize the securing arrangement wherein the fastening members 2| are not threaded into said knob.

While a preferred embodiment of the invention has been illustrated and described, the invention is not limited thereto, but is capable of such modifications and other embodiments as may occur to those skilled in the art.

I claim:

1. A manual control mechanism for apparatus whose operation is to be controlled by a manually rotatable member, comprising a rotatable member to be actuated having an annular projection, a fiat resilient element extending diametrically across the end of said projection, said element having transversely elongated apertures at its places of engagement with the end of said projection, screws extending through said apertures to secure said element to said projection, said apertures permitting adjustment of said element relative to said member, said element having turned end portions adjacent to the outer wall of said projection, and a manually rotatable member having an annular projection surrounding said first annular projection, the surrounding projection having internal recesses seating said end portions and frictionally engaging the same to effect firm attachment of said members.

2. A manual control mechanism for apparatus whose operation is to be controlled by a manually rotatable member, comprising a rotatable member to be actuated having an annular projection, a flat resilient element extending diametrically across the end of said projection, said element having transversely elongated apertures at its places of engagement with the end of said projection, screws extending through said apertures to secure said element to said projection, said apertures permitting adjustment of said element relative to said member, said element having turned end portions adjacent to the outer wall of said projection and bowed outwardly from said wall, and a manually rotatable member having an annular projection surrounding said first annular projection, the surrounding projection having internal recesses seating said end portions and exerting pressure thereon, each bowed end portion of said element acting as a spring to efiect firm attachment of said members.

3. In apparatus whose operation is to be contrclied by manually rotatable member, a casing having a circular cpening, a rotatable member within said casing to be actuated from outside the casing, an annular projection cn said member extending within said opening in spaced relation to the circumference of the opening, a flat resilient element extending diametrically across the end of said projection, element having transversely elongated apertures at its places of engagement with the end of said projection, screws extending through said apertures to secure said element to said projection, aper tures permitting adjustment of said ei 'nent relative to said member, said element ha b end portions adjacent to the outer wall of said projection, and a manually rotatabie member covering said opening and having an annular projection extending within said opening in surrounding relaticn to said first annular projection, said surrounding projection having internal recesses seating said end portions and frictionally engaging the same to effect firm attachment of said members.

i. In an apparatus whose operation to be controlled by a manually rotatable member, a casing having a circular opening, a rotatable member within said casing to be actuated from outside the casing, an annular projec on said member extending within said cper in spaced relation to the circumference of the opening, a flat resilient element extending diametrically across the end of said projection, said element having transversely elongated apertures at its places of engagement with the end of said projection, screws extending through said apertures to secure said element to said projection, said apertures permitting adjustment of said ele ent relative to said member, said element having turned end portions adjacent to the outer wall of said projec tion and bowed outwardly from said wall, and a manually rotatable member covering said opening and having an annular projection extending within said opening in surrounding relation to said first annular projection, said surrounding projection having internal recesses seating said end portions and exerting pressure thereon, each bowed end portion of said element acting as a spring to efiect firm attachment of said members.

5. In an apparatus whose operation is to be controlled by a manually rotatable member, a casing having a circular opening, a rotatable member within said casing to be actuated from outside the casing, an annular projection on said member extending within said opening in spaced relation to the circumference of the opening, a fiat resilient element extending diametrically across the end of said projection, said element having transversely elongated apertures at its places of engagement with the end of said projection, screws extending through said apertures to secure said element to said projection, said apertures permitting adjustment of said element relative to said member, said element having turned end portions adjacent to the outer wall of said projection, and a manually rotatable member covering said opening and having an annular projection extending within said opening in surrounding relation to said first annular projection, said surrounding projection having internal recesses seating said end portions and frictionally engaging the same to effect firm attachment of said members.

6. In an apparatus whose operation is to be controlled by a manually rotatable member, a casing having a circular opening, a rotatable member within said casing to be actuated from outside the casing, an annular projection on said member extending within said opening in spaced relation to the circumference of the opening, a fiat resilient element extending diametrically across the end of said projection, said element having transversely elongated apertures at its places of engagement with the end of said projection, screws extending through said apertures to secure said element to said projection, said apertures permitting adjustment of said element relative to said member, said element having turned end portions adjacent to the outer wall of said projection and bowed outwardly from said wall, and a manually rotatable member covering said opening and having an annular projection extending Within said opening in surrounding relation to said first annular projection, said surrounding projeotion having internal recesses seating said end portions and exerting pressure thereon, each bowed end portion of said element acting as a spring to eiTect firm attachment of said members.

WILLIAM MACNAMARA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,794,638 Mueller Mar. 3, 1931 1,815,164 Scofield July 21, 1931 1,935,560 Herold Nov. 14, 1933 2,161,956 Robertson June 13, 1939 2,301,169 Engstrom Nov. 3, 1942 2,342,276 Hehemann Feb. 22, 1944 2,593,609 Rhodes Apr. 22, 1952 

